MC3 process – No, Albert Einstein has not been reincarnated at Aerontec. The high speed MC3 saw – or multi-contour-cut-core system – is a development by the company to cut precut sheets of foam into double-cut, triple-cut and flexi-cut sheets depending on the end application.

Cut to size: Aerontec specialises in high-accuracy foam cutting factory

AERONTEC Composite Technology has made a substantial investment in foam cutting and finishing technology in order to support composite manufacturers, specifically the burgeoning boat-building sector.

Aerontec, a leader in composite technology in Africa, recently unveiled its new foam cutting and processing equipment at an industry open day at its plant in Montague Gardens, Cape Town. It has commissioned a number of specialised cutting systems and also a multi-contour cut saw technology which it developed internally, making it one of the most sophisticated composite foam cutting centres in the Southern Hemisphere, and the only such plant in Africa.

The foam sheets are supplied mainly to boat and yacht builders, where the foams are vacuum bagged or infused with resin for use in hull constructions as well as virtually all structural components and compartments on sailing vessels. The obvious advantage here is that the resin-infused sheet – as a composite component – is considerably lighter than alternative material options, and also offers the advantage of low water absorption.

Although the boat-building sector in South Africa is currently exceptionally buoyant (there’s some good news for you!), maritime use is not the sole application: a myriad applications exist in the transport, automotive, construction, and other sectors.

The PVC and PET foam sheets – ranging in density from 40 to 250kg/m³ – are imported from Europe and arrive in block stock in dimensions varying according to the density and type, with the smaller sizes being for the denser (heavier) foams. The saws are then used to cut the sheet into precise thicknesses as required. The sheet slicing operation is done by means of a special computerized foam saw and cuts to 200-micron tolerance over a sheet.

A main advantage for Aerontec is that its equipment is able to cut at previously unachievable speeds, and the quick turnaround has seen demand grow. Previously SA boat builders were having sheets processed and finished overseas, with extended delivery times, often of months duration. This had the effect of delaying the entire boat-building operation. Aerontec’s service has thus enabled a major transition in the sector. It is also able to service crisis orders (which happen more frequently than expected, as anyone involved in a JIT production situation can attest), which previously would have been impossible.

Aerontec has the ability to cut sheet down to 2 mm thick – which is quite an achievement when you consider the relatively large sizes of the sheets (it has developed a simple and ingenious method to achieve such thin cuts). However, demand appears to be greatest for sheet in the 10-25mm range.

Blyth and his team achieved another breakthrough by creating a specialized system to cut sheets that can be formed to tight curves or small radii. This advanced system, called ‘MC³‘, or “multi-cut contour core”, has an upper and lower bank of special blades, that cut partially into the foam sheet in one direction and then rotate the sheet 90 degrees to cut across the first axis, making the double cut sheet more flexible and allowing for enhanced resin infusion.

When placed in the mould, the double-cut sheet easily conforms to the contour required by the boat builder. If greater flexibility is required, additional cuts can be made in the sheet. In this application, the special blade penetrates only partly into the sheet, allowing it to retain its shape and integrity while also being flexible. Aerontec has also developed machinery to drill perforations into sheets to allow for resin infusion or vacuum bagging processes, with a proprietary drilling machine designed to have a small footprint in the factory.

Aerontec has assembled a team of professional, technical people to assist in this technology, with Gideon Els and John Grala in Cape Town and Arno Seyfert in the Eastern Cape area. These and other appointments have seen the company become a leader in the category in the process which has also been a major boost to the South African yacht building fraternity.